Airway management device and method of manufacture

ABSTRACT

An airway management device comprising a body having a proximal end for receiving an oxygen supply tube and an distal end for insertion into a trachea of a patient; said body including a linear portion adjacent to the proximal end and a curved portion adjacent to the distal end; said body including an external shell and having a first bore through said shell for receiving the oxygen supply tube; wherein flexural strength for said airway management device is provided by said shell.

This application is a divisional of U.S. Application Ser. No. 15/117,267filed on Aug. 8, 2016, which is a National Stage of PCT/SG2015/000035filed on Feb. 9, 2015, both of which are incorporated herein byreference.

FIELD OF THE INVENTION

The invention relates to laryngeal devices, particularly those used forintubation of patients.

BACKGROUND

Several existing devices are used for facilitating spontaneous breathingin anaesthetised patients; traditionally, the Endotracheal Tube (ETT)and more recently the Laryngeal Mask Airway (LMA). The majority of thesedevices use an inflatable cuff(s) to create the anatomical seal and as aconsequence there is an incidence of co-morbidity associated with theiruse; both physiological and anatomical. Subsequent refinement of the LMAhas resulted in the development and introduction of supraglottic airwaydevices (SAD) with gastric drainage (GD). The reported advantages beingease of insertion, haemodynamic stability, decreased morbidity, improvedrespiratory mechanics and reduced incidence of pulmonary aspiration. Analternative development uses a pre-formed and non-inflatable cuff.Disadvantages of SAD with GD primarily relate to the configuration ofthe distal tip becoming bulbous by the presence of the gastric tubepassing through the inflatable cuff and the associated structuresemployed; to present a flat profile of the distal tip when theinflatable cuff is deflated immediately prior to deployment and; preventocclusion of the drain tube after the SAD is deployed and inflated insitu.

The visco-elastic characteristics of the materials used for constructionof the various SAD's exert significant influence over the ability of thedevice to deliver the above stated advantages and contributesignificantly to the disadvantages. SAD's use the same materials asexisting LMA devices. Semi rigid PVC, vinyl elastomers and liquidsilicone rubbers are predominant in combinations comprising a more rigidairway with a softer inflatable cuff whilst thermoplastic elastomers(TPE) are used for versions exhibiting a non-inflatable cuff. Thosedevices using PVC and LSR require the use of adhesives and solvents forbonding and joining the different components during manufacture. SAD'susing TPE do not require adhesives as they are essentially a one piecemore rigid airway tube covered with TPE material to form the requiredshape without an inflatable cuff.

SUMMARY OF INVENTION

In a first aspect the invention provides an airway management devicecomprising a body having a proximal end for receiving an oxygen supplytube and an distal end for insertion into a trachea of a patient; saidbody including a linear portion adjacent to the proximal end and acurved portion adjacent to the distal end; said body including anexternal shell and having a first bore through said shell for receivingthe oxygen supply tube; wherein flexural strength for said airwaymanagement device is provided by said shell.

It will be appreciated that the first bore will include an adequateinternal diameter to accommodate the oxygen supply tube in the form ofan endotracheal tube.

In a second aspect the invention provides an airway management devicecomprising a body having a proximal end for receiving an oxygen supplytube and an distal end for insertion into a trachea of a patient; saidbody including a linear portion adjacent to the proximal end and acurved portion adjacent to the distal end, and a passage arranged toreceive a gastric drain tube; a toroidal shaped membrane having a firstand second opposed edged, said first edge moulded to a correspondingportion of the body and the second edge moulded to a correspondingsecond portion of the body, said first and second portions in spacedrelation, the membrane forming an inflatable cuff.

Accordingly, the shell acts as an exoskeleton, protecting the oxygensupply and any other device placed therein during the insertion process.Further, by providing a first bore of sufficient size to receive theoxygen supply tube, the body will include a moment of inertia for thecross-sectional shape to provide a high degree of stiffness. Thecross-sectional shape and selection of material may therefore allowconsiderable scope for selecting the required flexural stiffness for theairway management device. In the current embodiment, the body may simplybe referred to as an airway tube.

The first bore may be a non-symmetrical shape having two lobes, and thusproviding two portions arranged to receive and position the oxygensupply tube in one lobe, or a first passage, and an endoscope in theother lobe or second passage. By shaping the first bore, and inparticular, the lobes the oxygen supply tube and endoscope may beconfined to the particular lobe and so separate from each other, despitebeing positioned within an open first bore.

The body may include a second bore for containing a gastric drain tube.In the case of having the first and second passages as mentioned above,the second bore may then be considered a third passage.

The device according to the present invention may use methods ofmanufacturing that do not require adhesives. Rather, in one embodiment,it may utilise the self-adhesive properties of softer and more elasticTPE to the more rigid polypropylene substrate. In terms ofvisco-elasticity, a polyolefin material such as polypropylene may beused for the more rigid airway and TPE compound (using the samepolypropylene as the base material) may be used for the inflatable cuffwhich offers superior elastic response and reduced hysteresis. By virtueof doing so, it allows for the introduction of numerous and desirablefeatures for a SAD with GD.

Furthermore, the invention describes a SAD with GD that in addition tomaintaining an airway as described, it also provides for blindintubation simultaneous with gastric access and the ability to visuallyevaluate in situ via endoscopy. Prior art describes LMA and SAD that donot offer such diverse functionality.

A possible application of the device according to the present inventionmay include where the patient is to be transferred to an intensive carefacility. In such instances the LMA may be removed and replaced with anendotracheal tube.

An advantage of this invention may include that the device itself, byvirtue of the airway tube structure, guides the ET Tube into positionquickly and effectively with minimal trauma and loss of oxygen supply ifintubation becomes a necessary requirement toward protecting thewellbeing of the patient. Positioning of the ET Tube may then beconfirmed via endoscopy. The device described by the invention may thenbe removed whilst the ET Tube remains in situ.

BRIEF DESCRIPTION OF DRAWINGS

It will be convenient to further describe the present invention withrespect to the accompanying drawings that illustrate possiblearrangements of the invention. Other arrangements of the invention arepossible, and consequently the particularity of the accompanyingdrawings is not to be understood as superseding the generality of thepreceding description of the invention.

FIG. 1 is an isometric view of a body of an airway management deviceaccording to one embodiment of the present invention;

FIG. 2 is an isometric view of an insert for the body of FIG. 1;

FIG. 3 is an isometric view of the body of FIG. 1;

FIG. 4 is an isometric view of the insert of FIG. 2;

FIG. 5 is an isometric view of an oxygen supply adaptor of an airwaymanagement device according to one embodiment of the present invention;

FIG. 6 is a cross sectional view of the body of FIG. 7;

FIG. 6a is a detail cross sectional view of the body of FIG. 7;

FIG. 7 is an isometric view of the body of FIG. 1;

FIG. 8 is an isometric view of the body of FIG. 1;

FIG. 9 is an elevation view of the body of FIG. 1;

FIG. 10 is a plan view of the body of FIG. 1;

FIG. 11 is a front view of a body of an airway management deviceaccording to a further embodiment of the present invention;

FIG. 12 is a back view of the body of FIG. 11;

FIG. 13 is a detail cross sectional view of the body of FIG. 12;

FIG. 14 is a detail cross sectional view of the body of FIG. 12;

FIG. 15 is an isometric and cross sectional view of the body of FIG. 12;

FIG. 16 is an isometric view of the body of FIG. 12;

FIG. 17 is an isometric of a receiving tube of an airway managementdevice according to a further embodiment of the present invention;

FIG. 18 is a back of a body of an airway management device according toa further embodiment of the present invention;

FIG. 19 is a back of a body of an airway management device according toa further embodiment of the present invention;

FIG. 20 is a side elevation view of the body of FIG. 18;

FIG. 21 is a side elevation view of the body of FIG. 19;

FIG. 22 is a back elevation view of the body of FIG. 18;

FIG. 23 is a back elevation view of the body of FIG. 19;

FIG. 24 is an isometric view of a body of an airway management deviceaccording to a still further embodiment of the present invention;

FIG. 25 is an isometric view of the body of FIG. 24.

DESCRIPTION OF INVENTION

In the context of this description, the invention is henceforthdescribed as if it were inserted in a supinely positioned patient. Theairway management device includes a body, such as the airway tube (FIGS.1 and 3) extending from the proximal end 1 of the device through to thedistal tip 2. The horizontal cross section A-A (FIG. 6) through thestraight portion of the proximal airway tube, shows the primary 3 andsecondary passage 4 configured either side of the median plane. Thisconfiguration forms a shell providing a first moment of area greaterthan a similarly dimensioned circular or elliptical cross section. Thisprovides the device with sufficient flexural strength and so acting asan exoskeleton as compared with prior art devices where much of theflexural strength is derived from components within the device, and sodemonstrating an endo-skeleton structure.

Inserted into the airway tube proximal opening is an adaptor (FIGS. 5and 17), which facilitates connection to an oxygen supply as well ascombining into a more rigid structure able to cope with and tofacilitate the forces of circumduction during insertion. The paralleland sagittal planar relationship of these two passages defines anadditional partial posterior channel 5 that; together with anintermediate strip (FIGS. 2 and 4), creates a laterally offset thirdpassage to facilitate gastric drainage.

Cross section A-A (FIG. 6) progresses inferiorly through an anatomicallyapproximated curvature 6 of approximately 101 degrees (FIG. 9), parallelto the median plane, whereupon it transitions from a closed crosssection to an open cross section (FIGS. 8 and 9) coinciding with theventral opening of the device 7, where the primary and secondarypassages terminate openly. Within this opening, the primary passageprovides gaseous communication. When the adaptor is removed, thisprimary passage 3 allows for blind intubation (FIG. 10). The secondarypassage 4 provides for endoscopic access during blind intubation as wellas a secondary passage for spontaneous breathing during blindintubation.

Continuing inferiorly from this transition, the airway tube crosssection maintains the semi-circular contour of the partial posteriorchannel 5 until reaching the proximal end 8 of the medial slot 9, afeature congruent with the anterior or ventral opening. When viewedanteriorly toward the frontal plane (FIGS. 6 and 10), the medial slotprovides a route of progressive curvature for gastric drainage, from thepartial posterior channel 5 through the medial slot to the anterior sideof the distal airway tube; aligning the route for gastric drainage tothe median plane of the distal tip 10; allowing the passing of a gastricdrainage or suction tube with minimal frictional resistance.

Attached to the posterior of the airway tube is the intermediate strip(FIGS. 2 and 4) which exhibits curvature 6 in the sagittal planematching the airway tube and horizontal cross section 11 providinggeometric conformance and attachment to the airway tube (FIGS. 6 and 6a). The proximal intermediate strip (FIGS. 9 and 10) is defined by atubular feature 12 that serves as the entry point for gastric drainageor suction tube; and whose median axis when viewed laterally, adopts anangle of approximately 23.5 degrees with the horizontal plane coincidentwith the median axis 13 through the proximal end of the airway tube(FIGS. 9 and 21). When positioned on the airway tube, the intermediatestrip covers the partial posterior channel 5 which is essentially anelongate recess which together defines a third passage as a route forgastric drainage. The intermediate strip, once positioned, is flush withan external surface of the body of the device. The distal end of theintermediate strip terminates at the proximal end of the aforementionedmedial slot 8. Continuing inferiorly to the distal extremity 2, theairway tube cross section progressively reduces in width and firstmoment of area. Horizontal cross sections throughout this transitionexhibit ventrally concave curvature i.e. maintaining the posteriorcontour 34 were the intermediate strip (FIGS. 2, 4 and 9) to continueuntil the distal extremity of the airway tube.

When combined with the elastic properties of the polyolefin material,the ventrally concave curvature parallel to the medial slot 33 a andhorizontally through 33 b the medial slot creates a compound curvature(FIG. 15) or partial conical spring (Belleville washer) that encouragesan immediate elastic response from the polyolefin material duringflexure; thus maintaining contact between posterior airway tube and theposterior hypo-pharynx during insertion, without excessive forcecontributing to co-morbidity and soft tissue damage.

In pure mechanical terms, the distal end of the airway tube can beconsidered as the fixed support, whilst the airway tube by itself can beconsidered to act as a cantilever beam. Force exerted through thestraight proximal portion of the airway tube during insertionconcentrates flexion and extension through a horizontal axis coincidentwith two laterally opposed slots 23. The primary passage being larger indiameter than the secondary passage allows a degree of rotation aroundthe medial axis of the proximal airway tube that can be transferred astorsion through to the distal tip. SAD's using semi-rigid PVC materialsfor the airway tube behave in a viscous manner i.e. when force isapplied they resist shear and exhibit linear strain (relationshipbetween change in length to original length) for the duration of theapplied force. However, these forces are dissipated into the PVCmaterial such that when force is released, PVC will not immediatelyrespond and return to its original state. This lost energy, orhysteresis, is a significant disadvantage of prior art based on PVCmaterials. Polyolefin materials such as polypropylene exhibit a superiorvisco-elastic response, characterised by elastic rather than viscousresponse.

During insertion, the forces transferred through the airway tube aremanifested by circumduction. As a consequence, hysteresis in thematerials used by existing prior may prevent the distal tip beingcorrectly in situ with the upper oesophageal sphincter. Prior artdescribes the possibility of the distal tip entering the larynx or, thedistal tip of the LMA or SAD may fold under, a phenomenon described asdown-folding. Unlike other LMA or SAD, this invention uses an airwaytube that extends from the proximal end to the distal tip and whose formand function utilise the more immediate visco-elastic response of arigid polyolefin material. Where other SAD's describe a ventraldisplacement of the distal tip in relation to a dorsal or posteriorreference point on the airway tube to better conform to the anatomy,this invention provides for a wide range of flexional response thatobviates the ventral displacement described by prior art.

Protruding from the external surface of the gastric drain tube openingin closest proximity to the adaptor (FIG. 16), a raised step 14 isdefined that has a corresponding cut out (FIG. 17) or notch 43 in theouter surface of the adaptor. This raised step retains and prevents theadaptor from separating away from the airway tube (FIG. 20). When viewedsuperiorly toward the distal tip (FIG. 7), the proximal end 12 of thegastric drain tube is aligned with the median plane of the airway tubei.e. both passages share common a mid-plane (FIG. 7). It must be notedthat the mid-plane of the airway tube is with reference to the lateralextremities of the airway tube rather than an alignment with the primaryor secondary passage. To provide a primary passage of sufficientinternal diameter to accommodate the insertion of an ETT and blindintubation, the third passage is laterally offset and divided by animpermeable barrier (posterior surface of airway tube) to ensuresimultaneous blind intubation and gastric access.

As the median axis of the proximal opening (FIG. 9) approaches anintersection with the median axis of the adaptor and airway tube 13 a,the tubular cross section transitions increasingly elliptical and nolonger exhibits an enclosed perimeter, having opened up 15 to straddlethe proximal airway tube (FIG. 2). When a gastric drainage suction tubeis inserted through the tubular feature 12, the distal tip of thesuction tube will make tangential contact 16 with posterior surface ofthe primary passage (FIG. 3). Further insertion deflects the suctiontube laterally, seeking alignment with the supporting structure of ribs17 defining the posterior channel or third passage in this region. Thesuction tube can then be guided inferiorly to exit at the distal tip ofthe device 20.

Proximally, the intermediate strip is attached by 4 latches, 2 per sidepositioned laterally 18 where the intermediate strip straddles theairway tube. Coinciding at the tangent where the straddling straightsection of the airway tube terminates and the curvature 6 begins, theintermediate strip narrows abruptly 19. The supporting structure of ribs17 follow the curvature of the airway tube 6; opposing ribs 11 aintegral with the intermediate strip (FIG. 6a ) provide alignment andminimal interference, sufficient to provide for aforementionedattachment. Ribs 11 a and 17 progressively diminish and terminate at theproximal end of the medial slot 8.

Having described the airway tube, intermediate strip and adaptor, any orall of which may be manufactured from polyolefin material; thedescription now focuses on the inflatable cuff manufactured from athermoplastic elastomer (TPE) compounded from the same base polyolefinmaterial. This in itself provides the means of assembly for the devicedescribed herein. The self-adhering property of TPE, adhere theintermediate strip to the airway tube and create an open thin walledcuff membrane by virtue of an initial injection moulding processes; asubsequent injection moulding process entraps the open membrane andcreates an airtight and inflatable cuff, integral to the form andfunction of the device.

Viewed anteriorly toward the frontal plane (FIG. 11), the initialinjection moulding process surrounds the perimeter of the distal airwaytube with an elliptical shape cuff membrane of TPE, in a generallytoroidal shape about the airway tube. In a specific embodiment, the cuffmembrane may be characterised by; a distal tip whose curvature and widthfacilitate the tubular distal opening of the third passage 20 or gastricdrain tube; lateral extremities 21 defined by curvature extendingsuperiorly and tangential to the distal tip; an increasing rate ofchange of curvature that closes the elliptical shape at the median plane22, just superior to the horizontal axis through two laterally opposedslots 23 and; an enclosed third passage or gastric drain tube 24,totally covering the medial slot 9 and whose contour and curvature 31reconcile with that of the partial posterior channel 5. It will beappreciated that in alternative embodiments, the membrane may be avariety of open shapes, which may allow closure through a secondmoulding process to seal the open membrane and thus permit inflation ofthe cuff.

Horizontal cross sections B-B and C-C (FIGS. 13 and 14) illustrate theventral or anterior opening 7 through which the primary and secondarypassages exit. With respect to FIG. 14, the perimeter of the ventralopening is defined by a thin walled inflatable cuff membrane exhibitingan elliptical section 25. Adhered in the first instance to the perimeterof distal airway tube 26 and continuing tangentially from the immediateanterior of the airway tube toward its lateral extremity and normal tothe edge of the airway tube. The method of manufacturing requires thecuff membrane to be open along the posterior opening 27 of the perimeter(FIGS. 12 and 14), except for a region surrounding the distal opening(FIG. 13) of the gastric drain tube that is moulded into a closedsection 28 defining the configuration of the inflatable cuff surroundingthe distal drain tube. To this end, as a result of the first injectionmoulding step, the cuff is in the form of an open toroidal shape havingthe membrane open along a periphery of the toroid and adjacent to theperiphery of the airway tube.

With reference to FIG. 8, the thickness of airway tube along theperimeter 26 varies from 1.00 26 a to 0.5 mm 26 b combines with thecompound curvature 33 at the distal airway tube to provide flexuralarticulation rather than flexure of the distal tip around a fixedhorizontal axis. The thickness of the inflatable cuff membrane variesbetween 0.25 mm (leading edge of posterior opening 27) and 1.50 mm alongthe perimeter of the distal airway tube 26. All other cuff membrane wallthicknesses are optimised to provide for the ideal inflated shape andmechanical strength e.g. that portion of the inflatable cuff membrane(FIGS. 11, 20 and 21) surrounding a small tubular port 29 for attachingan inflation tube 29 a extruded from thermoplastic elastomer (FIGS. 24and 25) and equipped at its proximal end with an inflation balloon 29 band check valve allowing gaseous communication with the inflatable cuff.

It is a feature of this invention that the distal portion of the gastricdrainage tube may not intersect the inflated volume of the cuff (FIGS.13 and 14). In this embodiment the outside diameter may not be directlyexposed to the inflation pressure within the inflatable cuff; wallthickness of the gastric drainage requires no reinforcement structure toprevent occlusion; thereby avoiding a bulbous distal cuff configuration.Instead, and consistent with the closed section 28, the inflatable cuffmembrane 25 is moulded into a closed tubular section 30 concentric withthe third passage or gastric drain tube 24 creating a free space, orchamber, 32 adjacent to the tip of the device, and between theinflatable membrane and the distal third passage particularly about theaperture through which the gastric drainage tube projects. When in situand inflated, the closed section of cuff membrane 30 will not expand toan extent that all free space 32 is eliminated and the gastric draintube 24 compressed and occluded. The chamber 32 therefore provides a anexpansion buffer, the size of which may be determined through design soas to accommodate sufficient inflation of the cuff. The cuff willtherefore expand to within close proximity, providing support to thethird passage, or gastric drain tube 24, and the distal opening 20against the upper oesophageal sphincter.

Furthermore, immediately superior to the distal opening, the anterior ofdistal airway tube compound curvature 33 defines the internal posteriorsurface of the third passage or gastric drain tube; the narrow width andcurvature of the airway tube; the reducing thickness 26 b and; thesurrounding contour 34 of self-adhered TPE elastomer, minimise thedeflated thickness of the distal tip. The elastic response of thepolyolefin airway tube is manifest at the distal tip, now assisted bythe softer TPE. This configuration keeps combined thickness of materialsto a minimum, a characteristics evident when the cuff is deflated priorto deployment, negating the potentially bulbous nature of the distalcuff and gastric drainage supporting structure.

The contour of TPE adhering 34 to the distal anterior airway tube (FIG.13), having defined the closed section 28, progresses superiorly alongthe progressive curvature 31 of the medial slot 9, blending theresultant posterior contour 35 smoothly onto the intermediate strip,where it locates against the proximal end 8 of the medial slot. At thisjuncture the TPE diverts either side of the intermediate strip (FIGS. 7and 12) filling the sagittal planar voids 36 defined by the intermediatestrip locating against the posterior curvature of the airway tube 6.Proximally, at the juncture of the abruptly narrowing intermediate strip19, the TPE 37 converges to surround the latches 18 and the intermediatestrip in its entirety where it straddles the airway tube; the union ofthe intermediate strip and the airway tube is completed. Surrounded byTPE, the sealed union creates an enclosed third passage or gastric draintube with proximal and distal opening.

The angle 13 of the tubular feature relative to the adaptor (FIGS. 16and 17) combined with the elastic nature of the TPE allows the user to;apply leverage to the tubular feature 12; in a direction 40 such thatthe angle of incidence through the retaining step 14 relative to thefrontal plane (FIG. 9) is reduced and; remove the adaptor for insertionof an endotracheal tube or endoscope.

The adaptor can be returned to its original position by inserting thedistal end 41 into the proximal airway tube opening 42 and pushing itposteriorly. Once the notch 43 in the adaptor encounters the raised step14 on the tubular feature 12; a moderate increase in pressure willenable the adaptor to snap back into the home position; the mating face44 of the adaptor (FIG. 5) is pressed into and creates an airtight sealagainst the TPE 45 covering the proximal end 1 airway tube andintermediate strip and; a cylindrical cut-out 46 in the adaptor providesa minimal clearance against the tubular feature 12.

The subsequent injection moulding process provides a core and cavitythat locates the leading edge of the open cuff membrane 27 firmlyagainst an airway portion such as the posterior distal airway tubeperimeter 26. TPE interacts with the leading peripheral edges,entrapping them and blending with the already complete distal closedsection 28 and conforming to the finished inflatable cuff contourdefined by the injection mould core and cavity so as to close thetoroidal cuff. A further embodiment (FIG. 12) of this interactionencourages the TPE to further entrap the leading edge via small cut-outs47 and adhere it directly to the posterior of the distal airway tube.

The finished contour of the distal portion (FIGS. 18, 20 and 22) addsadditional TPE to the initial posterior contour 35 of the airway tube,wrapping around and completing a sealed circumference of the airway tube48; creating an airtight inflatable cuff. A further embodiment of thiscircumferential blend (FIGS. 19, 21 and 23) shows the step 49 taperingaway to a smooth blend 50 around the circumference of the airway tube.

The inflatable cuff membrane completes the manufacturing of the devicedescribed by this invention, without the need for adhesives or solvents.Using entirely polyolefin based materials achieves a more ecologicalsustainable alternative to PVC and vinyl elastomers that may containDEHP plasticisers or, LSR that cannot be recycled and similarlyre-processed due to the fact that it is a thermoset material whose crosslinking during moulding cannot be reversed.

In a further aspect of the present invention, the arrangement of thepassage for receiving gastric drainage tube may be applied to an airwaymanagement device of the prior art. Further, the method of manufacturingthe cuff in a two part construction may also be applied as an inventionseparate to the shell arrangement described previously. To this end, thethird passage described previously, may be a distinct and discreteaddition to an airway management device and consequently may simply bedescribed as a passage when an equivalent first and second passage, asdescribed above is not clearly defined or in fact not present.

The invention claimed is:
 1. A method of forming an inflatable cuff foran airway management device, comprising the steps of: injection mouldinga membrane about an airway tube, said membrane including an open length,then; closing said open length of said membrane against said airway tubevia molding and so forming the inflatable cuff.
 2. The method accordingto claim 1 wherein the membrane is in the shape of an open toroid. 3.The method according to claim 1 wherein the closing step includes asecond injection moulding of a section onto said open length and sosealing said open length.
 4. The method according to claim 1 furtherincluding the steps of: positioning an intermediate strip along anelongate recess of said airway tube so as to define a passage betweenthe intermediate strip and the elongate recess; and sealing saidintermediate strip using a moulding process.
 5. The method according toclaim 4, wherein the injection moulding of the membrane includes themoulding process to seal the intermediate strip.
 6. The method accordingto claim 1 further including, before the injection moulding of themembrane, the steps of: positioning an intermediate strip along anelongate recess of said airway tube so as to define a passage betweenthe intermediate strip and the elongate recess; and sealing saidintermediate strip using a moulding process.
 7. A method of forming aninflatable cuff for an airway management device, comprising the stepsof: injection moulding a membrane about an airway tube of said device,said membrane including an open length, then; closing said open lengthof said membrane against said airway tube and so forming the inflatablecuff, wherein the closing step includes a second injection moulding of asection onto said open length and so sealing said open length.
 8. Themethod according to claim 7 wherein the membrane is in the shape of anopen toroid.
 9. The method according to claim 7 further including thesteps of: positioning an intermediate strip along an elongate recess ofsaid airway tube so as to define a passage between the intermediatestrip and the elongate recess; and sealing said intermediate strip usinga moulding process.
 10. The method according to claim 9, wherein theinjection moulding of the membrane includes the moulding process to sealthe intermediate strip.
 11. A method of forming an airway managementdevice, comprising the steps of: providing an airway tube, then; first,moulding a membrane about said airway tube, said membrane including anopen length in a toroidal shape, then; second, moulding of a sectiononto said open length of said membrane by closing said open lengthagainst said airway tube and so sealing said open length and forming aninflatable cuff.
 12. The method according to claim 11 wherein themembrane is in the shape of an open toroid.
 13. The method according toclaim 11 further including the steps of: positioning an intermediatestrip along an elongate recess of said airway tube so as to define apassage between the intermediate strip and the elongate recess; andsealing said intermediate strip using a moulding process.
 14. The methodaccording to claim 13, wherein the injection moulding of the membraneincludes the moulding process to seal the intermediate strip.